/* Copyright 2007-2008 dnAnalytics Project.
 *
 * Contributors to this file:
 * Patrick van der Velde
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * * Redistributions of source code must retain the above copyright notice, this 
 *   list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice, 
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * * Neither the name of the dnAnalytics Project nor the names of its contributors
 *   may be used to endorse or promote products derived from this software without
 *   specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Diagnostics;
using dnAnalytics.LinearAlgebra;
using dnAnalytics.LinearAlgebra.Solvers;
using dnAnalytics.LinearAlgebra.Solvers.Preconditioners;
using NUnit.Framework;

namespace dnAnalytics.Tests.LinearAlgebra.Solvers.Preconditioners
{
    public abstract class PreconditionerTest
    {
        protected const double s_Epsilon = 1e-10;

        internal SparseMatrix CreateUnitMatrix(int size)
        {
            SparseMatrix matrix = new SparseMatrix(size);
            for (int i = 0; i < size; i++)
            {
                matrix[i, i] = 2;
            }
            return matrix;
        }

        protected Vector CreateStandardBcVector(int size)
        {
            Vector vector = new DenseVector(size);
            for (int i = 0; i < size; i++)
            {
                vector[i] = i + 1;
            }
            return vector;
        }

        internal abstract IPreConditioner CreatePreconditioner();

        protected abstract void CheckResult(IPreConditioner preconditioner, SparseMatrix matrix, Vector vector, Vector result);

        [Test]
        public void ApproximateWithUnitMatrixReturningNewVector()
        {
            int size = 10;
            SparseMatrix newMatrix = CreateUnitMatrix(size);
            Vector vector = CreateStandardBcVector(size);

            IPreConditioner preconditioner = CreatePreconditioner();
            preconditioner.Initialize(newMatrix);

            Vector result = preconditioner.Approximate(vector);

            CheckResult(preconditioner, newMatrix, vector, result);
        }

        [Test]
        public void ApproximateReturningOldVector()
        {
            int size = 10;
            SparseMatrix newMatrix = CreateUnitMatrix(size);
            Vector vector = CreateStandardBcVector(size);

            IPreConditioner preconditioner = CreatePreconditioner();
            preconditioner.Initialize(newMatrix);

            Vector result = new DenseVector(vector.Count);
            preconditioner.Approximate(vector, result);

            CheckResult(preconditioner, newMatrix, vector, result);
        }

        [Test]
        [ExpectedException(typeof(NotConformableException))]
        public void ApproximateWithVectorWithIncorrectLength()
        {
            int size = 10;
            SparseMatrix newMatrix = CreateUnitMatrix(size);
            Vector vector = CreateStandardBcVector(size);

            IPreConditioner preconditioner = CreatePreconditioner();
            preconditioner.Initialize(newMatrix);

            Vector result = new DenseVector(vector.Count + 10);
            preconditioner.Approximate(vector, result);
        }

        [Test]
        [ExpectedException(typeof(ArgumentNullException))]
        public void ApproximateWithNullVector()
        {
            int size = 10;
            SparseMatrix newMatrix = CreateUnitMatrix(size);
            Vector vector = CreateStandardBcVector(size);

            IPreConditioner preconditioner = CreatePreconditioner();
            preconditioner.Initialize(newMatrix);

            Vector result = new DenseVector(vector.Count + 10);
            preconditioner.Approximate(null, result);
        }

        [Test]
        [ExpectedException(typeof(ArgumentNullException))]
        public void ApproximateWithNullResultVector()
        {
            int size = 10;
            SparseMatrix newMatrix = CreateUnitMatrix(size);
            Vector vector = CreateStandardBcVector(size);

            IPreConditioner preconditioner = CreatePreconditioner();
            preconditioner.Initialize(newMatrix);

            Vector result = null;
            preconditioner.Approximate(vector, result);
        }

        [Test]
        [ExpectedException(typeof(MissingMatrixException))]
        public void ApproximateWithNonInitializedPreconditioner()
        {
            int size = 10;
            SparseMatrix newMatrix = CreateUnitMatrix(size);
            Vector vector = CreateStandardBcVector(size);

            IPreConditioner preconditioner = CreatePreconditioner();

            Vector result = preconditioner.Approximate(vector);
        }
    }
}